Velocity oscillations in confined channel flows of concentrated colloidal suspensions

Abstract

We study the pressure-driven flow of concentrated colloids confined in glass micro-channels at the single particle level using fast confocal microscopy. For channel to particle size ratios $a/\bar{D}\lesssim 30$, the flow rate of the suspended particles shows fluctuations. These turn into regular oscillations for higher confinements ($a/\bar{D}\simeq 20$). We present evidence to link these oscillations with the relative flow of solvent and particles (permeation) and the effect of confinement on shear thickening.

4 pages, 6 figures

References in corpus (2)

• Shear thickening of cornstarch suspensions as a re-entrant jamming transition
• Shear zones and wall slip in the capillary flow of concentrated colloidal suspensions

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